In recent years, information terminal equipment including a personal computer and a server, and communication equipment such as an internet router and optical communication are required to process a large volume of information at high speeds, and thus increases in speed and frequency of an electrical signal are in progress. With this, a printed circuit board material used therein is required to achieve lower dielectric constant and lower dielectric loss tangent besides properties such as flame retardancy, heat resistance and peel strength against a copper foil or the like, which have been conventionally required, thus leading to various attempts for the constitution of the resin composition in order to meet these property requirements.
In order to impart electrical properties to these materials, there is known a recipe in which a resin having a low-dielectric constant and a low dielectric loss tangent such as a fluorine resin, a cyanate ester resin, a polyphenylene ether resin, and a vinyl compound mainly comprising styrene is contained in a resin composition (see, for example, Patent Literature 1). Generally, a laminate using such compounds, which is inferior in flame retardancy, requires to contain a halogenated compound in a resin composition in order to impart flame retardancy (see, for example, Patent Literatures 2 and 3). However, the use of halogenated compounds causes an environmental problem that toxic substances such as dioxin may occur at the time of incineration.
Hence, for example, an addition of a compound mainly comprising phosphorus and nitrogen has been examined as an approach for achieving flame retardancy without containing any halogenated compound (see, for example, Patent Literatures 4 and 5). However, nitrogen compounds may produce harmful nitrogen oxide, and also phosphorus compounds which have been conventionally used cause a problem that heat resistance is deteriorated, namely, the glass transition temperature (Tg) of the resin composition is decreased as an addition amount is increased to achieve flame retardancy (see, for example, Patent Literatures 6 and 7).